生态环境学报2024，Vol.33Issue(12)：1882-1890,9.DOI:10.16258/j.cnki.1674-5906.2024.12.006
不同污染天气下大气颗粒物及化学成分干沉降通量的粒径演变特征
Size-resolved Aerosol Dry Deposition and Chemical Composition during Haze Weather in Beijing,China
摘要
Abstract
Wet and dry deposition processes are the major removal mechanisms for atmospheric pollutants and are important sources of nutrients and toxins in ecosystems.Compared to wet deposition,dry deposition is more difficult to measure directly;thus,an inferential approach is often used to estimate dry deposition fluxes.In this study,size-resolved particle dry deposition velocities(Vd)were calculated using classical parameterization,which was then combined with measured size-and chemically resolved ambient concentrations to estimate the dry deposition fluxes of particulate matter,with a focus on heavy pollution days.The calculated size-resolved Vd of particulate matter varied from 0.037 to 0.50 cm·s-1,with increased values at high wind speeds and low relative humidity.The maximum and minimum values of Vd occurred at 5.8‒9 μm and 0.65‒1.1 μm or 1.1‒2.1 μm,respectively.With a minimum Vd value at a particle size of 1.1 μm,Vd increased as the particle size decreased or increased,reflecting the different dominant microphysical mechanisms of dry deposition for different particle sizes.During the observation period,dry deposition fluxes of particulate matter ranged from 9.41 to 108.71 mg·m-2·d-1,with a mean value of 36.65 mg·m-2·d-1.The concentration and Vd had a greater influence on the dry deposition fluxes of the coarse and fine particles,respectively.During heavy polluted days,the dry deposition fluxes of particles at each size range showed an upward trend,among which the dry deposition of secondary aerosols of nitrate,sulfate and ammoniums showed an obvious"size distribution shift"phenomenon.Such a phenomenon occurred in both January 2013 and January 2022,indicating that persistent heavily polluted weather in the North China Plain may increase the input of particulate species to the surface ecosystem through dry deposition.关键词
干沉降/大气颗粒物/粒径分布/重污染天气/化学成分Key words
dry deposition/particulate matter/size distribution/heavy polluted weather/chemical composition分类
资源环境引用本文复制引用
张孟燊,陈志辉,徐敏,贾世国,田世丽,李嘉伟,胡波,潘月鹏..不同污染天气下大气颗粒物及化学成分干沉降通量的粒径演变特征[J].生态环境学报,2024,33(12):1882-1890,9.基金项目
国家重点研发计划项目(2022YFC3704802) （2022YFC3704802）
中国科学院基础与交叉前沿科研先导专项(XDB0760400) （XDB0760400）
